The present invention relates to new 23-oxo (keto) and 23-imino derivatives of the compounds C(26,27)-epoxy and C(14,15;26,27)-diepoxy-LL-F28249 compounds collectively defined as LL-F28249. These LL-F28249 compounds are produced by the fermentation of the microorganism Streptomyces cyaneogriseus subspecies noncyanogenus having deposit accession no. NRRL-15773. The morphological characteristics, compounds and methods for their production are disclosed in European Application No. 170,006, incorporated herein by reference. The C(26,27)-epoxy- and C(14,15;26,27)-diepoxy-LL-F28249 compounds are derived by epoxidation of the LL-F28249 compounds and disclosed in concurrently filed U.S. application for Letters Pat. Ser. No. 022847, Asato et al, hereby incorporated by reference.
The C(26,27)-epoxy- and C(14,15;26,27)-diepoxy-LL-F28249.alpha., .beta., .epsilon., .zeta., .theta. and .iota. compounds are complex macrolids which have a 23-hydroxy substituent, as well as hydroxy groups at the 5 and 7 positions. The selective oxidation of the 23-hydroxy group to a 23-oxo (keto) group and the subsequent derivatization of the oxo group to afford 23-imino derivatives are the subject matter of the present invention. These 23-oxo (keto) and 23-imino derivatives of the C(26,27)-epoxy and C(14,15;26,27)-diepoxy-LL-F28249.alpha., .beta., .epsilon., .zeta., .theta. and .iota. compounds are useful for the prevention, treatment or control of helminths, ectoparasites, insects, acarids and nematodes in warm-blooded animals and agricultural crops.